Signal relaying system



Filed Feb. 20, 1932 2 Sheets-Sheet l TRANS.

AND

REC. STA.

I I CC ZL O LE -o E 0: n1 -r O m 1 15 W 1 W E a: 2 LU E 1 E Y31 W m H INVENTOR T g o 5 DR. A.N. GOLDSMITH 2 -I" BY E a I W ATTORNEY Sept. 26, 1933. r N, GQLDSWTH i 1,927,827

' SIGNAL nzmnue SYSTEM Filed Feb. 20-, 1932 2 Sheets-Sheet 2 l .{L Y I 3 3113 61 FILTER RECTIFIER DELAY RECTIFIER CIRCUIT T DELAY L CIRCUIT i E'J DELAY CIRCUIT I (1 l Li TJ POWER REC-"HER RECTIFIER AMPL. u \-|NPUT 2 RECT'FIER FILTER FILTER INVENTOR OR. A N GOLDSMITH ATTORNEY Patented Sept. 26, 1933 in 15927327 7 SIGNAL RELAYING SYSTEM A Ifred N L rj Golds nithgNew York, N. Y., assignori t Radib Ahilibfl, a b iil di' ifiofi V 1 of Delaware ApplicationFebruary 20, 1932:. Serial No. 594,238 'colaiifis. (Cl. 250-45) This invention relates to the transmissionof 1y, this'effect is due to the characteristics of electromagnetic waves at the" lower wave lengths, which characteristics are similar *inany respects to those of light waves. The inter position ofjany object in the path of transmission, it has 5 been found, affects; to anhext'ent at least, the ability of astation to receive the transmitting signals. It may'thus'be seen that the condition of the local topographyis an element of conside' eration the design of an ultra-short wave com munication' t V object of the present invention isto enable the reception of electromagnetic waves high efficiency at points remote from the transmitting statioii' irrespective of atmospheric confditifons or the naturepf the intervening topography.

' Anotherobjectfis'toprovide'arelay or so-cal le'd repeater station which is capable o'f automatically reversing its direction of transmission; i A featureof thepresent invention is'the'special electromagnetic" switching relay employed in the a repeating station for reversedly connecting either of two antenna'to the statipnequipment. This feature permits the automatic conditioning of the'system for-transrni'ssion'or reception; in either oftwo'directions; without the aid of operators at theintermediate repeating stations. Other objects and features will appear-later intheidetailed description;

municatioirsystem' having a plurality of repeater stations located between the terminal transmittingand'receiving'stations. E'ach'of these repeaters is comprisedfof a plurality of directionalan ranged to be effective in diiferent' directions to wardthe', next adjacent repeater stations. Col-1+ inelitd between the "directional antennae at each repeater there is provided suitable equipment for amplifying the signals received prior to their tennae" which are individually positioned or a'r-f.

ing apparatus is adapted to respond to a special 1 signal of a predetermined nature which is sent out from the transmitting station. time-delay element in the circuit permits a slight interval of time to elapse 'before the reversing equipment functions in order to insure proper conditioning of all stations for transmission the desired direction. Thus, there is avoided a'condition whereby different repeaters of the radio communication system are pointed in opposite di- 5 rections. a

In the accompanying drawings, Figure 1 illus- V trates; diagrammatically, a radio communication system embodying the principles of the present invention, and Figures 2 and 3 illustrate diiierent' 7 types of repeater stations for use in' the present invention 1 Referring to Figure 1, there are shown two transmitting and receiving stations A and B betweenwhich it is desired to transmit signals. As indicated in the drawings by the direction of the arrows, station A is arranged to transmit sig-' nals and station B to' receive signals. Intermediate A'and are a plurality of repeater stations- R-' and R'"; These repeaters are provided 30 I with apluralitypf directional antenna, one or .from the 'transmitting station, this'case station A,-' for conditioning the repeater to receive and transmitthe reverse direction. This featur'willbe described subsequently in connection with the circuits of'F'igures Z'and 3.

If desiredyf a 1 plurality of transmission paths may e provided leet'we'e'ii certain repeating s't'a' tions. such management-1s advantageous when the tra smission of sighals'over a particular path is t times 'diflicultf uch as may be the case when the territory loetween the" two: repeat- 7 ers'" is mountainousor crossedby rivers; Mainftenance considerationsare also; a' factor which may make it advisable to provide plurality of paths. I

f l f such-an arrangement is used,;special repeat"- ersfsuch' as R/Qare provided at'the splitting ,105

points oftheradio' tra'risini'ssi'or'i-line-if These speciarrepeaters aredesigned-*wreive over" one directional antenna and to transmit overei ther of tvvo 'o'the'rf directional antefiiii A 3 second switching relay, which is responsive to a'specia'l 11 0 adapted to switch the equipment at the special is conditioned for receiving signals overantenna 1 and for transmitting the; amplified signals over .antenna 2. Whenshaf-t 8 is attracted by the lower repeater R" from'one transmitting antenna to the other. This is described later in connection with Figure 3.

; Figure 2 illustrates arepeaterof the type indicated by referencecha'racter.Rlin Figure 1, and

-wherein' the same operation will be repeated.

comprises two directional antenna: .1 and '2. radio frequency power amplifier 3, having input and output circuits for ampliiying the received signals,is shown associated with the antennae l and 2 and with an electromagnetic switching relay 4. This relay comprises an upper winding 5 and a lower winding 6, andisadapted to respond toa special signal received over the transmis sion circuit} actuating shaft 8 in either one of two directions. the upper winding 5, then the repeater. station winding 6 of relay 4,,the directions of reception and transmission are, reversed This shaft is arranged tore-main in its iast actuated positionuntil a reversing signal isreceived.

The special signal sent from the transmitting 7 station for conditioning therepeater to relay; sige.

nals -in a desired direction may be a code signal comprisinga series; of dots and dashes, a high frequency 'tone signal of a predetermined irequency and having .aqdefinite duration, or any other suitable signal. The apparatus responsive to .thi s]special signal for actuating-electromagnetic switch 4 may be any type well known in the art, such as a signal selector. For-purposes of describing the present invention, a sustained toned signal of relatively. considerable length will be employed to reverse the direction oi the repeater.

.A delay circuit 9 is utilized toretard the action of the specialsignal. This circuit has a two-fold purpose, first,.to permit the reception of the specialsignal at all rep'eatersbeiore the di- .rection;oftransmissionis reversedso as to avoid 1 a condition wherebydifferent sections of the sys- I 45 tern are'pointedinoppositedirections, and second, to insure, the. operation of switch,.relay 4 only upon the reception ofthe correct tone signal .of a definite duration. {This delay element pre vents the operation of the switch when the repeater is energizedbygstray excitation on the signallingfrequencm such as may'be due toa lightning fiashor other electrical disturbance. I

The time-delay element ma comprise any type well known in the art and may be either of the mechanical (dashpot) .or ofthe electrical type,

analogous to a very slightly damped resonant circuit, orofanyptherconvenient'form.- v

The directional antennaev 1 and. 2 are pointed directly' at the next adjacent station to which it is desired to transmit or from which it is desired to receive signals. It may be advisable to stagger the repeater stations slightly to avoid one station from affecting another station which isdirectly the line of transmission, but which is more remote than its adjacent/station. These antennae .may be highly ..directional or less. so, in order to feed broad swathes of territory. 1 From this point of- 'v'iewtheideal. directional characteristic 'wouldj'be more orless of the cardioid type, as nearly circular as possible, and with a sharp dimple? toward the scribed.

a" that directional antenna 1 is pointed Assuming When this shaftis'actuated by associated" repeater two. special signals.

Filter circuit 14 is arranged to pass a narrow frequencies Of'the special signal, which frequencies are outside the range of the message signals.

In this manner, the message waves are prevented from actuating relay 4.

The reception of the special tone signal from the transmittingstation will cause the actuation of switch relay 4. This special signal is rectified ordemodulated by the apparatus 15 and allowed to pass through filter. 14 to the primary winding of transformer 16. The special tone signal is again rectified by rectifier 17 prior. toentering delay circuit 9 from which the signal current flows over lead 18 through the lower winding 6 of switch.4, through the upperrightcontacts 19 and 20, overlead 21 and back to rectifier 1'7 to actuate switch relay 4. All contac'tsof switch relay 1,4 are, of course, insulated from the shaft.

The armature shaft 8 is'thus attrtcteddownwardly, causing the opening of contacts. 19 and 20 and the closure of contacts 22 and 23. Since 7 shaft. 8 is pivoted at 24 its downward movement will cause the opening of contacts 10', lland 12, 13,, and the closure of contacts 25, 26'and 2'7, 28. The operation of relay 4, it will be noted, connectsthe input circuit of amplifier 3 to the anvtenna 2 overthe upper inner. contacts 28, 2'7 and theoutput circuit of amplifier 3 to antenna 1 over the upper outer contacts '25, 26. The repeater is now in condition. to receive signals .over antenna 2 and to transmit the amplifier signals over antenna 1.

, Similarly,a special reverse signal received over band of frequencies corresponding to the desired antennaf2 will. actuate the. upper winding of switch relay 4 an obvious manner, to connect the input andoutput circuits of amplifier apparatus 3 to antennae'l andfl2 respectively.

Figure 3 illustrates a repeater station quite similar to that shown in Figure 2 except for the addition of another directional antenna and another switching relay with associated apparatus .for operatively associating either one of: two

directional antennae 2 and 40 with antennal.

The operation,'in most respects, is identical. with that hereinabove described in connection with Figurea- L A second switching relay 30.is. showncon" nected to a second time-delay element 31. Switch 30 is adapted to respond to a second special tone signal for changing the direction of transmission .or reception from antenna 2 to antenna 40, or vice vers'a. This second signaLof course, is of a frequency quite different from thespecial signal adapted to operate switch- 4. Filters 14 a'nd32 arerespectiVeIy arranged to'discriminate between the two special signals. It. is to be understood that thesignal which is adapted to operate switch -.30 will not affect any of the switches 4 in any ofthe repeater stations. I t

.In practice,stationsA and B at both ends of the communication systemwill be both transemitting and receiving stations providedwiththe necessary equipmentjfor the transmission of the Only the terminal station which happens to be transmitting will be able to A or B, or bothA and B,"may be broadcasting stations and maybe provided with auxiliary telephone communication apparatus. g

Although this'invention findsparticular application in the ultra-short wave field, it is to be distinctly understood that it is not limited thereto, but may be utilized advantageously in the transmission of all types of electromagnetic waves. A system mime type herein described may be used for the broadcasting of television service. a 1

It is also to be understoodthat various modifi cations may be made in the "present invention without departing from the spirit and scope thereof. 1 V

I claim: 1

1. A short wave radio communication system comprising a transmitting station, a remote receiving station, anda plurality of intermediate repeating stations, each of said repeating stations comprising a directional antenna positioned to receive signal waves from its next adjacent repeating station located in the approximate direction of the transmitter, and a second directional antenna positioned to transmit signal rectional antennae for amplifying the received signal waves, an input circuit and an output circuit for said amplifying apparatus, and switching means for reversedly connecting said circuits to either of said two directional antenna. a

2. A short wave radio communication system :as defined in claim 1, characterized in this, that said switching means comprises electromagnetic termined signal. l 1

33. A relaying station for radio signal waves 7 comprising two directional antennae, each of said antennae being positioned in different directions, signal amplifying apparatus having input and output circuits, and switching means for reversedly connecting said circuits to either of said two directional antennae.

' 4. A relaying station for radio signal .waves cuit being coupled to said first antenna, switch a ing means for connecting said output circuit with either said second or third antennae, but not with both simultaneously, saidswitching means being adapted to respond to signals received over said first antenna. a i

5. A relaying station, for radio signal waves comprising two directional antenna, each of said antennae being positioned in difierent directions, signal amplifying apparatus having input and output circuits, and switching means for automatically reversedly connecting said circuits to either of said two directional antenna, said switching means being adapted to respond to a predetermined signal wave received by said station.

6. A relaying system for radio signal waves comprising a receiving directional antenna,and two transmitting directional antennae, signal amplifying apparatus having an input circuit coupled to said receiving antenna and an output circuit coupled to one of said two transmitting antennae, and switching means responsive to a predetermined signal received over said receiving antenna for connecting said output circuit from 'said one transmitting antenna to the other transmitting antenna. relay apparatus adapted to respond to a prede- ALFRED N. GOLDSMITH. 

